Answering important questions about human disease mechanism, diagnosis and therapy requires that molecular tools be coupled effectively to detailed clinical phenotyping, particularly in patients followed prospectively over time. Bioassay Core (Core B) is designed to serve the Research Base as a centralized resource for standardized preparation and storage of clinical samples, and for conducting a range of high quality, low-cost assays on clinically derived material. The latter will include both assays performed using commercial kits, as well as custom-designed assays. In the past 5 years, the Bioassay Core has proven its ability to serve the Research base by providing crucial biospecimens and assays for numerous peer reviewed publications, abstracts, and investigator-initiated grant proposals. The aim of this proposal is to continue growing this critical resource which fuels innovation, collaboration and facilitiates studies focused on a wide range of rheumatic diseases by researchers across the spectrum of investigation. Major services and assays that will be provided by the Bioassay Core include sample preparation (eg, serum, DNA, RNA, PBMCs), storage and retrieval, as well as ELISAs, autoantibody analyses and immunohistochemistry. The Core will also help to connect investigators to other appropriate institutional Cores, and participate in outreach activities. Core B will also provide training, management and quality control to staff in the Clinical Centers to ensure that best practice standards for processing, recordkeeping, and ensuring fidelity of labeling are uniformly applied, and to aid Investigators to take any custom assays established in the Core back to their own labs. The Core will be led by Dr. Livia Casciola-Rosen, who has been Director of this project for the past 3 years, and has many years experience in immunology and assay development. Additional leadership will be provided by Dr. Felipe Andrade and Dr. Laura Gutierrez. The availability of central systems to facilitate sample collection, processing, storage and assays has been critical to enabling scholarship on human rheumatic disease cohorts. The close coordination of this Core with the Administrative, Flow Cytometry and Human Subjects Research and Analytical Cores provides an extremely powerful matrix to maximize synergies in the environment.